//-------------------------------------------------------------------
//	timedgcd.cpp		(revised version of our 'gcdcalc.c')
//
//	This program accepts two integers as command-line arguments,
//	then it computes and displays their greatest common divisor.
//
//	   compile using:  $ gcc fastgcd.s timedgcd.s -o timedgcd
//	   execute using:  $ ./timedgcd <int1> <int2>
//
//	programmer: ALLAN CRUSE
//	written on: 29 MAR 2006
//	revised on: 03 APR 2006 -- to perform a timing comparison
//-------------------------------------------------------------------

#include <stdio.h>	// for printf() 
#include <stdlib.h>	// for atoi()

extern "C" int gcd( int, int );
unsigned long long tsc( void ) { asm(" rdtsc" ); }

unsigned long long	stamp0, stamp1, stamp2, stamp3;

int gcd1( int m, int n )
{
	int	p = ( m < 0 ) ? -m : m;
	int	q = ( n < 0 ) ? -n : n;
	while ( q != 0 ) { int r = p % q; p = q; q = r; }
	return	p;
}


int main( int argc, char **argv )
{
	if ( argc < 3 ) return 1;

	int	m = atoi( argv[1] );
	int	n = atoi( argv[2] );

	stamp0 = tsc();	
	int	g1 = gcd1( m, n );
	stamp1 = tsc();	

	stamp2 = tsc();	
	int	g2 = gcd( m, n );
	stamp3 = tsc();	

	printf( "\n\n\t gcd1( %d , %d ) = %d      ", m, n, g1 );
	printf( "         gcd( %d , %d ) = %d  \n\n", m, n, g2 );

	printf( "\tstamp1 = %20llu   stamp3 = %20llu \n", stamp1, stamp3 );  
	printf( "\tstamp0 = %20llu   stamp2 = %20llu \n", stamp0, stamp2 );
	printf( "    cpu-cycles = %20llu ", stamp1 - stamp0 );
	printf( "           %20llu \n\n", stamp3 - stamp2 );
}